[clang][frontend] Require invocation to construct CompilerInstance (#137668)

This PR makes it so that `CompilerInvocation` needs to be provided to
`CompilerInstance` on construction. There are a couple of benefits in my
view:
* Making it impossible to mis-use some `CompilerInstance` APIs. For
example there are cases, where `createDiagnostics()` was called before
`setInvocation()`, causing the `DiagnosticEngine` to use the
default-constructed `DiagnosticOptions` instead of the intended ones.
* This shrinks `CompilerInstance`'s state space.
* This makes it possible to access **the** invocation in
`CompilerInstance`'s constructor (to be used in a follow-up).

Author: jansvoboda11

clang-tools-extra/clang-include-fixer/IncludeFixer.cpp

@@ -89,8 +89,7 @@ bool IncludeFixerActionFactory::runInvocation(
   assert(Invocation->getFrontendOpts().Inputs.size() == 1);
 
   // Set up Clang.
-  clang::CompilerInstance Compiler(PCHContainerOps);
-  Compiler.setInvocation(std::move(Invocation));
+  CompilerInstance Compiler(std::move(Invocation), std::move(PCHContainerOps));
   Compiler.setFileManager(Files);
 
   // Create the compiler's actual diagnostics engine. We want to drop all

clang-tools-extra/clangd/Compiler.cpp

@@ -145,9 +145,7 @@ prepareCompilerInstance(std::unique_ptr<clang::CompilerInvocation> CI,
         CI->getFrontendOpts().Inputs[0].getFile(), Buffer.get());
   }
 
-  auto Clang = std::make_unique<CompilerInstance>(
-      std::make_shared<PCHContainerOperations>());
-  Clang->setInvocation(std::move(CI));
+  auto Clang = std::make_unique<CompilerInstance>(std::move(CI));
   Clang->createDiagnostics(*VFS, &DiagsClient, false);
 
   if (auto VFSWithRemapping = createVFSFromCompilerInvocation(

clang-tools-extra/include-cleaner/unittests/RecordTest.cpp

@@ -618,14 +618,14 @@ TEST_F(PragmaIncludeTest, ExportInUnnamedBuffer) {
                  llvm::MemoryBuffer::getMemBufferCopy(Extra.getValue(),
                                                       /*BufferName=*/""));
 
-  auto Clang = std::make_unique<CompilerInstance>(
-      std::make_shared<PCHContainerOperations>());
-  Clang->createDiagnostics(*VFS);
+  auto DiagOpts = llvm::makeIntrusiveRefCnt<DiagnosticOptions>();
+  auto Diags = CompilerInstance::createDiagnostics(*VFS, DiagOpts.get());
+  auto Invocation = std::make_unique<CompilerInvocation>();
+  ASSERT_TRUE(CompilerInvocation::CreateFromArgs(*Invocation, {Filename.data()},
+                                                 *Diags, "clang"));
 
-  Clang->setInvocation(std::make_unique<CompilerInvocation>());
-  ASSERT_TRUE(CompilerInvocation::CreateFromArgs(
-      Clang->getInvocation(), {Filename.data()}, Clang->getDiagnostics(),
-      "clang"));
+  auto Clang = std::make_unique<CompilerInstance>(std::move(Invocation));
+  Clang->createDiagnostics(*VFS);
 
   auto *FM = Clang->createFileManager(VFS);
   ASSERT_TRUE(Clang->ExecuteAction(*Inputs.MakeAction()));

clang/include/clang/Frontend/CompilerInstance.h

@@ -204,6 +204,8 @@ class CompilerInstance : public ModuleLoader {
   void operator=(const CompilerInstance &) = delete;
 public:
   explicit CompilerInstance(
+      std::shared_ptr<CompilerInvocation> Invocation =
+          std::make_shared<CompilerInvocation>(),
       std::shared_ptr<PCHContainerOperations> PCHContainerOps =
           std::make_shared<PCHContainerOperations>(),
       ModuleCache *ModCache = nullptr);
@@ -251,18 +253,10 @@ class CompilerInstance : public ModuleLoader {
   /// @name Compiler Invocation and Options
   /// @{
 
-  bool hasInvocation() const { return Invocation != nullptr; }
-
-  CompilerInvocation &getInvocation() {
-    assert(Invocation && "Compiler instance has no invocation!");
-    return *Invocation;
-  }
+  CompilerInvocation &getInvocation() { return *Invocation; }
 
   std::shared_ptr<CompilerInvocation> getInvocationPtr() { return Invocation; }
 
-  /// setInvocation - Replace the current invocation.
-  void setInvocation(std::shared_ptr<CompilerInvocation> Value);
-
   /// Indicates whether we should (re)build the global module index.
   bool shouldBuildGlobalModuleIndex() const;
 

clang/lib/Frontend/ASTUnit.cpp

@@ -1162,9 +1162,8 @@ bool ASTUnit::Parse(std::shared_ptr<PCHContainerOperations> PCHContainerOps,
   }
 
   // Create the compiler instance to use for building the AST.
-  std::unique_ptr<CompilerInstance> Clang(
-      new CompilerInstance(std::move(PCHContainerOps)));
-  Clang->setInvocation(CCInvocation);
+  auto Clang = std::make_unique<CompilerInstance>(CCInvocation,
+                                                  std::move(PCHContainerOps));
 
   // Clean up on error, disengage it if the function returns successfully.
   auto CleanOnError = llvm::make_scope_exit([&]() {
@@ -1487,7 +1486,6 @@ void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
 void ASTUnit::transferASTDataFromCompilerInstance(CompilerInstance &CI) {
   // Steal the created target, context, and preprocessor if they have been
   // created.
-  assert(CI.hasInvocation() && "missing invocation");
   LangOpts = std::make_unique<LangOptions>(CI.getInvocation().getLangOpts());
   TheSema = CI.takeSema();
   Consumer = CI.takeASTConsumer();
@@ -1601,14 +1599,13 @@ ASTUnit *ASTUnit::LoadFromCompilerInvocationAction(
                         AST->getFileManager().getVirtualFileSystem());
 
   // Create the compiler instance to use for building the AST.
-  std::unique_ptr<CompilerInstance> Clang(
-      new CompilerInstance(std::move(PCHContainerOps)));
+  auto Clang = std::make_unique<CompilerInstance>(std::move(CI),
+                                                  std::move(PCHContainerOps));
 
   // Recover resources if we crash before exiting this method.
   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
     CICleanup(Clang.get());
 
-  Clang->setInvocation(std::move(CI));
   AST->OriginalSourceFile =
       std::string(Clang->getFrontendOpts().Inputs[0].getFile());
 
@@ -2232,15 +2229,14 @@ void ASTUnit::CodeComplete(
   LangOpts.SpellChecking = false;
   CCInvocation->getDiagnosticOpts().IgnoreWarnings = true;
 
-  std::unique_ptr<CompilerInstance> Clang(
-      new CompilerInstance(PCHContainerOps));
+  auto Clang = std::make_unique<CompilerInstance>(std::move(CCInvocation),
+                                                  PCHContainerOps);
 
   // Recover resources if we crash before exiting this method.
   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance>
     CICleanup(Clang.get());
 
-  auto &Inv = *CCInvocation;
-  Clang->setInvocation(std::move(CCInvocation));
+  auto &Inv = Clang->getInvocation();
   OriginalSourceFile =
       std::string(Clang->getFrontendOpts().Inputs[0].getFile());
 
@@ -2254,7 +2250,6 @@ void ASTUnit::CodeComplete(
 
   // Create the target instance.
   if (!Clang->createTarget()) {
-    Clang->setInvocation(nullptr);
     return;
   }
 

clang/lib/Frontend/ChainedIncludesSource.cpp

@@ -122,9 +122,8 @@ IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
     IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
         new DiagnosticsEngine(DiagID, &CI.getDiagnosticOpts(), DiagClient));
 
-    std::unique_ptr<CompilerInstance> Clang(
-        new CompilerInstance(CI.getPCHContainerOperations()));
-    Clang->setInvocation(std::move(CInvok));
+    auto Clang = std::make_unique<CompilerInstance>(
+        std::move(CInvok), CI.getPCHContainerOperations());
     Clang->setDiagnostics(Diags.get());
     Clang->setTarget(TargetInfo::CreateTargetInfo(
         Clang->getDiagnostics(), Clang->getInvocation().getTargetOpts()));

clang/lib/Frontend/CompilerInstance.cpp

@@ -67,22 +67,20 @@
 using namespace clang;
 
 CompilerInstance::CompilerInstance(
+    std::shared_ptr<CompilerInvocation> Invocation,
     std::shared_ptr<PCHContainerOperations> PCHContainerOps,
     ModuleCache *ModCache)
     : ModuleLoader(/*BuildingModule=*/ModCache),
-      Invocation(new CompilerInvocation()),
+      Invocation(std::move(Invocation)),
       ModCache(ModCache ? ModCache : createCrossProcessModuleCache()),
-      ThePCHContainerOperations(std::move(PCHContainerOps)) {}
+      ThePCHContainerOperations(std::move(PCHContainerOps)) {
+  assert(this->Invocation && "Invocation must not be null");
+}
 
 CompilerInstance::~CompilerInstance() {
   assert(OutputFiles.empty() && "Still output files in flight?");
 }
 
-void CompilerInstance::setInvocation(
-    std::shared_ptr<CompilerInvocation> Value) {
-  Invocation = std::move(Value);
-}
-
 bool CompilerInstance::shouldBuildGlobalModuleIndex() const {
   return (BuildGlobalModuleIndex ||
           (TheASTReader && TheASTReader->isGlobalIndexUnavailable() &&
@@ -1210,11 +1208,10 @@ std::unique_ptr<CompilerInstance> CompilerInstance::cloneForModuleCompileImpl(
   // CompilerInstance::CompilerInstance is responsible for finalizing the
   // buffers to prevent use-after-frees.
   auto InstancePtr = std::make_unique<CompilerInstance>(
-      getPCHContainerOperations(), &getModuleCache());
+      std::move(Invocation), getPCHContainerOperations(), &getModuleCache());
   auto &Instance = *InstancePtr;
 
-  auto &Inv = *Invocation;
-  Instance.setInvocation(std::move(Invocation));
+  auto &Inv = Instance.getInvocation();
 
   if (ThreadSafeConfig) {
     Instance.createFileManager(ThreadSafeConfig->getVFS());

clang/lib/Frontend/PrecompiledPreamble.cpp

@@ -454,14 +454,13 @@ llvm::ErrorOr<PrecompiledPreamble> PrecompiledPreamble::Build(
   PreprocessorOpts.GeneratePreamble = true;
 
   // Create the compiler instance to use for building the precompiled preamble.
-  std::unique_ptr<CompilerInstance> Clang(
-      new CompilerInstance(std::move(PCHContainerOps)));
+  auto Clang = std::make_unique<CompilerInstance>(std::move(PreambleInvocation),
+                                                  std::move(PCHContainerOps));
 
   // Recover resources if we crash before exiting this method.
   llvm::CrashRecoveryContextCleanupRegistrar<CompilerInstance> CICleanup(
       Clang.get());
 
-  Clang->setInvocation(std::move(PreambleInvocation));
   Clang->setDiagnostics(&Diagnostics);
 
   // Create the target instance.

clang/lib/Frontend/Rewrite/FrontendActions.cpp

@@ -242,10 +242,9 @@ class RewriteIncludesAction::RewriteImportsListener : public ASTReaderListener {
     (*OS) << '\n';
 
     // Rewrite the contents of the module in a separate compiler instance.
-    CompilerInstance Instance(CI.getPCHContainerOperations(),
-                              &CI.getModuleCache());
-    Instance.setInvocation(
-        std::make_shared<CompilerInvocation>(CI.getInvocation()));
+    CompilerInstance Instance(
+        std::make_shared<CompilerInvocation>(CI.getInvocation()),
+        CI.getPCHContainerOperations(), &CI.getModuleCache());
     Instance.createDiagnostics(
         CI.getVirtualFileSystem(),
         new ForwardingDiagnosticConsumer(CI.getDiagnosticClient()),

clang/lib/StaticAnalyzer/Frontend/ModelInjector.cpp

@@ -75,8 +75,8 @@ void ModelInjector::onBodySynthesis(const NamedDecl *D) {
 
   // Modules are parsed by a separate CompilerInstance, so this code mimics that
   // behavior for models
-  CompilerInstance Instance(CI.getPCHContainerOperations());
-  Instance.setInvocation(std::move(Invocation));
+  CompilerInstance Instance(std::move(Invocation),
+                            CI.getPCHContainerOperations());
   Instance.createDiagnostics(
       CI.getVirtualFileSystem(),
       new ForwardingDiagnosticConsumer(CI.getDiagnosticClient()),